A plurality of optical routes in an optical network are usually switched with use of optical switch devices. An optical switch device is simply referred as an optical switch. As the increasing of data traffic, optical switches have been developed allowing to switch with faster rate. An optical switch called a current drive type, for example, amplifies optical signals by injected current and enables fast switching by on-off controlling of the injection current.
The performances of the optical switches are generally so liable to be suffered from the operating temperature to vary the output amplitude of optical signal. Therefore, the optical communication apparatus with the optical switch usually performs thermal control of the optical switches. Japanese Laid-open Patent Publication 2004-117966 discloses an optical transmission apparatus which includes a measurement portion for measuring a temperature of an optical switch and a thermo-controlling portion for controlling the temperature of the optical switch.